I. Field of the Invention
The present invention relates generally to both the field of mobility assistance devices and the field of rescue and survival equipment. In particular, the present invention relates to a multifunctional winter walking staff which may serve as a means of survival in the event of breaking through thin ice into frigid water, or a means of rescue of a person or an animal who suffered such an event.
II. Brief Description of the Prior Art
Winter in northern climes presents a harsh, inhospitable environment to those who venture outdoors. Yet, the stark beauty of winter landscapes and the many opportunities for sport and recreation it offers are sufficiently rewarding to draw great many people outdoors in wintertime. Of the challenges attendant to winter outings, traversal of icy surfaces is particularly and insidiously perilous. Slipping on ice is an ever-present danger, one with potentially disastrous consequences when slipping off an ice ledge into frigid water. Similarly disastrous, but oftentimes unheeded, is the danger of breaking through thin ice into frigid water. The rapidity at which hypothermia sets in and the difficulty of climbing back onto the surrounding ice combine to render these events potentially lethal. (In this description and in the appended claims, an ice surface failure or any other departure from an ice surface which results in Inadvertent Immersion in Frigid Water is termed an “IIFW event”).
The aforementioned problems associated with traversing an ice surface can be mitigated in three ways: prevention, survival, and rescue. To reduce the risk of slipping on ice, traction augmentation devices have traditionally been used. Shoes and boots have been fitted with anti-slip soles, spiked cleats—integrated with the sole or mounted on a detachable frame (crampons)—and even strap-on chains. Though effective on ice, such specialized footwear must, inconveniently, be replaced with ordinary footwear off the ice (or fittings removed and carried along). Less effective, but more convenient means of prevention are walking canes fitted with pointed tips. One example of such an adaptation of a walking cane is proposed in patent application CA2082115A1 (Stewart Lewis, 1993); another, in patent application CA2679396A1 (Brian Mcgann, 2010).
Prevention of an IIFW event, of course, is best assured by avoiding thin ice areas of frozen lakes and rivers. Such surfaces, unfortunately, are not always discernible due to overlying snow, and even when visible, their thickness may easily be misjudged. Solutions designed to negotiate an IIFW event have focused, therefore, on means of survival and rescue.
To enable a person who sustained an IIFW event to attain a secure grip on the ice surface and pull himself/herself back onto it, specially adapted ice picks have been devised. An example of such a device is proposed in patent application W09411243A1 (Martti T. Hotti, 1994). A sharp-tipped, handheld pole that is intended to be used in a similar manner is taught in patent U.S. Pat. No. 5,827,098A (Alan D. Cunningham, 1998).
Effective as the aforementioned and other dedicated survival implements are, one must be mindful of the possibility of disaster on an outdoors excursion to carry along survival tools. One seldom contemplates this possibility, though, and most people do not carry survival tools with them on hikes. Moreover, the application of a device of either of the types described above to “claw” one's way back onto sound ice demands a certain level of athletic ability, which many people lack. Unless in possession of such a device, at the time of the incident, and of the ability to wield it effectively, a person who sustained an IIFW event will have great difficulty to exit the water and may be completely dependent on a timely rescue by a person close at hand to survive.
Rescue implements intended for an IIFW event include sleds, and various buoyant and shore-based access platforms—relatively large and heavy devices. Somewhat more portable are marine rescue implements designed for a man-overboard emergencies. The most ubiquitous of such implements is a tethered, weighted buoyant body to which is attached a looped strap or rope to be engaged by the person in need of rescue (“rescuee”, hereafter), with the rescue line stowed compactly within the buoyant body before deployment, and is extracted from it progressively when it is cast. One example of such a device is proposed in patent application WO2004/056653Al (Lars-Hakan Lendqvist, 2004). Another example is taught in patent U.S. Pat. No. 6,659,823B1 (Kirk Mosna, 2003). These implements are still too bulky to be truly portable, and are not likely to be carried along on terrestrial excursions. A similar but simpler type of marine rescue device is taught in patent US006575799B1 (Richard Stimpson, 2003) and patent U.S. Pat. No. 4,661,077A (Bruce S. Griffith, 1987). In these devices the rescue line is stowed separately from the buoyant body. Again, both devices are too unwieldy to be encumbered with on a hike.
Another type of marine rescue implement employs a tubular boom fitted at its distal end with a looped line by which to engage and pull to safety a person overboard. One example of such a device is taught in patent U.S. Pat. No. 4,599,074A (David E. Beckly, 1986), and another in patent U.S. Pat. No. 5,752,731A (Robert D. Crone, 1998). Deployed to effect rescue after an IIFW event, a device of this type would force the person attempting the rescue to approach the rescuee to within the limited reach of the device. This would subject the rescuer to the risk of breaking through the ice himself/herself. Under certain circumstances, such as when an VFW event occurs near a lakeside dock, a pole-mounted loop could be effective, but under more typical circumstances, the use of a pole-mounted loop to effect rescue after an IIFW event is inadvisable.
Pole-mounted hooks intended or suitable for rescue after an IIFW event are also known. One example is disclosed in patent U.S. Pat. No. 5,827,098A (Alan D. Cunningham, 1998). Another example is shown in patent U.S. Pat. No. 5,116,093A (O. Edward Burns, 1992). The forgoing comments respecting the limited utility of pole-mounted loops apply similarly to pole-mounted hooks.
A disadvantage shared by existing tethered rescue devices and pole-mounted loops and hooks is encountered when a rescue after an IIFW event is attempted far offshore on an open ice field. Due to the absence of accessible land fixtures to serve as anchorage and due to the minimal traction on ice, it may not be possible for the rescuer to exert the necessary pulling force on the rescue line or pole, after successful engagement with the rescuee, without the rescuer sliding or slipping on the ice surface.
There remains a need, evidently, for a means by which to effect rescue after an IIFW event, which overcomes the aforementioned shortcomings of existing solutions. The present invention addresses this need.